Paleontology News for Kids / Noticias Paleontológicas Para Niños

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Monthly Archives: January 2017

Joan Wiffen was born in 1922 in New Zealand. Her father thought education was wasted on girls, so Joan didn’t get to go to high school. When she grew up, she joined the Women’s Auxiliary Airforce during World War II.

Joan got married in 1953. After a time, her husband signed up to take a geology class, but got sick and couldn’t go. Joan eagerly took his spot in the class, remembering her love of fossils as a child. She saw on a geologic map that a nearby valley had ‘old reptilian bones’ and went out fossil hunting near her house. In 1975, she found a fossil! She knew it was a vertebra, part of the backbone of an animal, but didn’t know from what animal.

A replica of the vertebra Joan found. Photo by Marianna Terezow/GNS Science.

In 1979 she went on vacation to Australia and visited the Queensland Museum. She met Ralph Monar, a paleontologist there and noticed a familiar looking bone on his desk. It was a vertebra exactly like the one she had found! He told her it was part of a dinosaur tail. She had found the first dinosaur fossil from New Zealand!

Joan Wiffen at the site where she found her first fossils. Photo by NZPA/John Cowpland.

Ralph and Joan worked together on many projects and published dozens of papers. Because of Joan’s hard work, she was known as the Dinosaur Lady. Even though Joan had not gone to school, she received an honorary doctorate from the Massey University of New Zealand in 1994. She also received a special award from the Queen.

Last week, a new [fossil] was unveiled. This one comes from the oceans of the Ordovician period (around 450 million years ago) and it’s a trilobite.

(Above: Trilobites from Dinopedia and Pinterest)

Trilobites are extinct arthropods (spiders, insects, millipedes, centipedes, crabs, lobsters, scorpions and more). They only lived during the Paleozoic Era (542-251 million years ago), but they had around 17,000 species (there’s only 5,400 species of mammals)! Trilobites came in a huge variety of shapes and sizes. Some of them were over 70 cm long and some were only 1 cm long.

The name “trilobite” comes from the three lobes that make up its body – the two side lobes (pleural lobes) and the central lobe. Note: they are not named for their cephalon (head), thorax, and pygidial (butt) lobes.

2 ways to divide a trilobite.

Since arthropods shed their exoskeletons to grow, we have many fossils of the same species, showing how an individual develops.

This new fossil shows something egg-straordinary. It has eggs preserved with it! The eggs are located under the cephalon of the trilobite. Even though trilobite eggs have been found before, they’ve never been found with an adult trilobite!

Figure 1a, d, and e from the paper showing the fossil and the eggs underneath the cephalon.

From this we understand that trilobites carried their eggs outside of their body, but tucked underneath their heads. Not on [kite strings] like other extinct arthropods.

The reason paleontologists thought that hyoliths were molluscs is because of their cone-shaped shell, operculum (a cover for the shell opening), and because of the shape of their larvae. Hyoliths first appear in the Cambrian (541 million years ago) and lived throughout the Paleozoic (541-252 million years ago).

After examining 1500 specimens and looking at the soft tissue preserved in 254 of those specimens, the authors discovered that hyoliths actually contain a lophophore (a frilly feeding structure) and are more closely related to brachiopods.

A brachiopod showing its lophophore. From Visuals Unlimited.

This study highlights the need to continue to find and collect specimens, even if there are some already in other collections. It also shows us that with enough time, many scientific mysteries can be solved.

Figure 3a,b, and g from the paper showing the author’s interpretation of the fossils and their updated life reconstruction.

At the start of 2017, an [article] was published that reported on a new discovery about dinosaur teeth. The authors looked at the teeth of two species of dinosaur – Protoceratops andrewsi and Hypacrosaurus stebingeri.

Protoceratops on the left by Z. Chuang and Hypacrosaurus on the right by V. Kontantinov.

But not just any teeth. The authors examined the teeth of embryos (an embryo is a baby still inside its egg). Teeth grow day by day, and as they do, they leave lines inside the tooth – much like tree rings inside a tree. By counting these lines (called Von Ebner’s growth lines), we can see how old an animal is.

Figure 1 from the paper showing the Von Ebner lines in Hypacrosaurus in A and in Protoceratops in B, and a CT image of the jaw with a functional tooth in C.

But the authors did more than that. We know that embryos do not begin to form teeth immediately, and that sometimes ‘practice’ teeth can form and fall out before the final teeth (called functional teeth) are made. In fact, in crocodiles, functional teeth start to grow about 42% through their incubation period, after the jaws have formed. Using this information, and by counting the growth lines in the teeth, the authors estimated that Protoceratops babies incubate for a minimum of 83 days. The same math gives a calculation of 171 days for Hypacrosaurus.

Are you ready yet?? (Protoceratops with eggs by M. Kelly).

Today’s birds incubate their eggs for a maximum of 39-83 days (based on the size of the egg and other factors). This means that these dinosaurs incubated their eggs for over TWICE the time that birds today do. In the case of Hypacrosaurus, it’s almost HALF OF THE YEAR.

The authors point out that because of these long incubation times, adults and babies were more at risk of environmental changes and predators and could have contributed to their extinction.

I’m starting off the year with the [discovery] of a fossil plant. This fossil was found in a fossil caldera lake (a lake that forms inside the top of a volcano) that dates to the early Eocene in the province of Chubut, Argentina. The formation is called Laguna del Hunco.

A map of Argentina showing the location of the province of Chubut. From Wikipedia.

The fossil is of a fruit with a calyx (the leaves at the base of a flower or fruit that protect it) with 5 inflated lobes that completely surround an internal berry. These characteristics are exactly like the living tomatillo. Using these features and computer analysis, the authors know that the fossil belongs to Solanacaea (the nightshades like eggplant, tomatoes, and others) and can place it with the Physalis genus (tomatillos and groundcherries).

Figure 1A from the paper on the left, showing the new fossil. A living tomatillo on the right for comparison (From Gourmet Sleuths).

They named the fossil Physalis infinemudi (in fine mundi means ‘at the end of the world’ for Patagonia, where the fossil was found, and referring to the age of the fossil). The age of the fossil is particularly interesting. The authors date the fossil to 52.2 million years ago – 30 million years older than the other estimates of evolution for this group! This places the fossil during the last stages of the separation of Gondwana (the landmass made up of the southern continents: South America, Australia, Antarctica, Africa, India). This analysis, along with others, shows that many of the plants from Gondwana evolved much earlier than previous estimates had calculated.